Temperature-resistant and salt-resistant thick oil viscosity reducer and preparation method thereof

The invention belongs to the field of preparation of auxiliaries for oilfield development, and particularly relates to a temperature-resistant and salt-resistant thick oil viscosity reducer and a preparation method thereof. The preparation method comprises the following steps: reacting hydroquinone with ethylene oxide in the presence of a catalyst to generate an intermediate product; and reacting the purified intermediate product with chlorosulfonic acid in a solvent to generate a final product, namely the thick oil viscosity reducer. The structural general formula of the heavy oil viscosity reducer is shown in the specification, wherein n is an integer from 3 to 6. The thick oil viscosity reducer has the characteristics of low cost, good compatibility, strong adaptability to oil reservoirs, high viscosity reduction rate, high yield and simple preparation method; the maximum temperature resistance value of the heavy oil viscosity reducer reaches 350 DEG C, and the maximum salt resistance value reaches 200000